Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds non-obvious operational context: it returns format ids for create_lesson, warns against hard-coding ids, and states that no minutes are spent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded and short, with the key dependency on create_lesson stated first. It repeats the 'before create_lesson' guidance in the second sentence, which is mildly redundant but still useful for emphasis.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given zero parameters, no output schema, and a simple read-only listing operation, the description provides everything an agent needs: when to call it, what it returns conceptually, and how to use the returned ids.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so there are no parameter semantics to explain; the baseline for zero parameters is 4. The description appropriately focuses on output usage instead, noting that callers should read format ids here and pass them to create_lesson.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb and resource ('List video formats') and explicitly separates this tool from create_lesson, which is named as the consumer of the output. An agent can identify the tool's role without inspecting the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It states exactly when to use this tool: when the user asks which styles exist, or before create_lesson if the user named a style. The alternative path is implicit but clear enough because the description directly names create_lesson and explains the dependency.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.